Method for comprehensively recovering low-grade lead-zinc oxidized ore resources

Abstract

The invention relates to the technical field of non-ferrous metal metallurgy, in particular to a comprehensive recovery method for low-grade lead-zinc oxidized ore resources. According to the method, through a side-blown smelting furnace oxidation process and a fuming furnace reduction process, firstly, pyrometallurgy oxygen-enriched smelting is carried out, high-lead smoke dust and zinc-germanium-containing slag are produced, zinc oxide smoke dust is obtained through fuming reduction volatilization, then the zinc oxide smoke dust enters a zinc hydrometallurgy process, the high-lead smoke dust enters a pyrometallurgy lead smelting process for batching, and the zinc-germanium-containing slag is obtained. And finally, lead metal (rich in silver), zinc metal, germanium concentrate and tailings are generated. The method aims at achieving comprehensive recovery of low-grade lead-zinc oxidized ore resources by improving the recovery rate of lead and zinc in the low-grade lead-zinc oxidized ore and conducting cooperative treatment on silver, germanium and cadmium at the same time, and a new thought is provided for comprehensive recovery and large-scale industrial production of the low-grade lead-zinc oxidized ore resources.

Description

Technical Field

[0001] The present invention relates to the technical field of non-ferrous metal smelting, and particularly relates to a method for comprehensively recovering low-grade lead-zinc oxide ore resources. Background Art

[0002] China has rich reserves of lead-zinc mineral resources, but there are many lean ores and few rich ores. The lean ore structure is complex and often associated with impurities such as fluorine, chlorine, arsenic, cadmium, and mercury, making it difficult to process. Currently, domestic lead-zinc smelting enterprises generally have problems such as raw material gaps, declining grades of concentrate raw materials, high procurement costs for high-grade ore raw materials, high impurity components in low-grade lead-zinc ores, and high comprehensive smelting energy consumption. The smelting raw materials of lead-zinc enterprises are gradually transferred from high-grade lead sulfide concentrate to medium-low grade lead sulfide concentrate to lead oxide concentrate, zinc oxide concentrate to lead-zinc oxide ore to leaching residue materials to secondary zinc-containing materials such as steel plant zinc soot, and some enterprises rely on imported lead-zinc concentrates. With the continuous growth of China's lead-zinc smelting production capacity, the contradiction between high-grade and high-quality lead-zinc mineral resources and the raw material gap of smelting enterprises has become increasingly prominent, and it is necessary to smelt low-grade and complex lead-zinc oxide ores and high-fluorine and chlorine zinc oxide fumes; therefore, improving the comprehensive recovery and utilization technology of low-grade lead-zinc resources conforms to the new trend of industry development. At present, although there have been breakthroughs in the beneficiation technology of lead-zinc oxide ores in China, the recovery rates of lead and zinc metals are only about 80%, and there are problems such as high energy consumption and large slag volume in smelting low-grade lead-zinc oxide ores.

[0003] The smelting methods for low-grade lead-zinc oxide ore resources mainly include pyrometallurgical processes and hydrometallurgical processes. Among them, Chinese Patent CN106086457A (a method for resource utilization of low-grade lead-zinc oxide ore) realizes the utilization of low-grade lead-zinc oxide ore resources. However, the use of a rotary kiln has problems such as low recovery rates of precious metals such as silver, germanium, and indium associated with lead-zinc oxide ore, low zinc recovery efficiency, and relatively high labor intensity for cleaning kiln buildups.

[0004] In addition, Chinese Patent CN108456775B (a method for combined treatment of zinc-containing materials by side-blown melting and fuming blowing) proposes to form a mixed material by mixing lead-zinc symbiotic ore and zinc-containing materials such as zinc leaching residue in any proportion, adding it to a side-blown furnace for melting to obtain zinc oxide fumes with high F, Cl, and As content; the furnace slag is directly put into a fuming furnace for blowing, and the fumes from the fuming furnace are processed to obtain zinc oxide fumes with low F, Cl, and As content. However, this process mainly targets lead-zinc symbiotic ore containing F, Cl, and As, and the method of mixing raw materials in any proportion is not conducive to the recovery rates of precious metals such as lead, zinc, silver, germanium, and indium in low-grade lead-zinc oxide ore, and the problems of electrolytic sticking plates in zinc hydrometallurgy caused by F and Cl impurities cannot be ignored.

[0005] Therefore, it is necessary to propose a comprehensive resource recovery method for low-grade lead-zinc oxide ore to improve the recovery rate of lead and zinc in low-grade lead-zinc oxide ore, and to coordinately process silver, germanium and cadmium, so as to achieve comprehensive recovery of low-grade lead-zinc oxide ore resources.

[0006] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0007] The main purpose of this application is to provide a method for comprehensive recovery of low-grade lead-zinc oxide ore resources, which aims to improve the recovery rate of lead and zinc in low-grade lead-zinc oxide ore and simultaneously coordinate the treatment of silver, germanium and cadmium, thereby achieving comprehensive recovery of low-grade lead-zinc oxide ore resources, and providing a new idea for large-scale industrial production of comprehensive recovery of low-grade lead-zinc oxide ore resources.

[0008] To achieve the above object, the present invention provides a method for comprehensive recovery of low-grade lead-zinc oxide ore resources, the method comprising the following steps:

[0009] S1, mixing low-grade lead-zinc oxide ore, hydrometallurgical zinc leaching slag, iron slag, lump coal, quartz sand and secondary zinc-containing materials in a mass ratio of 4:4:2:2:2:1 to obtain a mixed ore;

[0010] The sum of lead and zinc grades in the low-grade lead-zinc oxide ore is greater than 10%, and the calcium grade is less than 35%;

[0011] The secondary zinc-containing materials include any two or more of zinc-containing iron slag, zinc-containing sulfate slag and pyrometallurgical lead slag;

[0012] S2, feeding the mixed ore described in S1 into a side-blown smelting furnace to obtain high-lead smoke and liquid zinc-containing slag;

[0013] S3, sending the liquid zinc-containing slag in S2 to a fuming furnace A, and obtaining zinc oxide fume A after smelting;

[0014] S4, mixing the high-lead smoke dust in S2 with lead slag, iron slag and lead concentrate in a mass ratio of 1:1:1:2, and sending the mixture into a top-blown smelting furnace to obtain molten lead-rich slag, and then periodically transporting the molten lead-rich slag to a side-blown reduction furnace to obtain crude lead and reduction slag;

[0015] The crude lead is electrolytically smelted and die-casted to obtain lead ingots and silver ingots;

[0016] S5, periodically sending the reducing slag described in S4 into a fuming furnace B to obtain zinc oxide dust B;

[0017] S6. Feed the zinc oxide soot A and zinc oxide soot B into the hydrometallurgical zinc smelting system to obtain germanium concentrate, zinc-containing filtrate, iron slag and lead slag. Return the lead slag and iron slag to S4 for batching. After the zinc-containing filtrate is purified and the impurities are removed, supernatant and germanium-containing filter residue are obtained;

[0018] The germanium-containing filter residue is calcined to obtain germanium concentrate;

[0019] The supernatant is purified, electrolyzed and cast to obtain zinc ingots.

[0020] Optionally, the mass ratio of FeO to SiO2 in the mixed ore is (1.3 - 1.5):1, and the mass ratio of CaO to SiO2 is (0.5 - 0.8):1.

[0021] Optionally, 24000 m 3 / h of high-pressure air and 4.5 t / h of pulverized coal are injected into the fuming furnace A in S3. The temperature in the furnace is 1150 - 1250 °C, and the smelting cycle is 3 hours / furnace.

[0022] Optionally, pulverized coal is injected into the top-blown smelting furnace in S4, and the temperature is controlled at 950 - 1050 °C. The conveying cycle of the molten lead-rich slag is 2.5 - 3.5 hours, and the temperature in the side-blown reduction furnace is 1050 - 1200 °C.

[0023] Optionally, pulverized coal and high-pressure air are injected into the fuming furnace B in S5, the smelting temperature is 1100 - 1250 °C, and the smelting cycle is 1.5 - 3 h / furnace.

[0024] Optionally, the calorific value of the pulverized coal is 4000 - 6500 kcal·kg -1 ; the fixed carbon content of the pulverized coal is ≥50%, the sulfur content is ≤2.5%, the volatile matter content accounts for 10% - 25%, the moisture content accounts for ≤2%, the ash content accounts for ≤30%, and the particle size ≤200 mesh accounts for more than 70% of the total volume of the pulverized coal.

[0025] Optionally, the supply system of the pulverized coal is the Reidker pulverized coal injection system, and the supply rate of the pulverized coal is 2 - 5.5 t / h.

[0026] Optionally, the particle size of the low-grade lead-zinc oxide ore in S1 is ≤10 mm; the moisture content of the secondary zinc-containing material is 10% - 18%; the moisture content in the mixed ore is <18%.

[0027] Optionally, the smelting temperature of the side-blown smelting furnace in S2 is 1150 - 1350 °C, and the smelting cycle is 2 - 4 h / furnace.

[0028] Optionally, smelting waste slag is generated in the fuming furnace A and the fuming furnace B. The smelting waste slag is quenched with water to obtain granulated slag, and the granulated slag is recycled as a raw material for cement building materials.

[0029] Principle of invention:

[0030] Low-grade lead-zinc oxidized ore contains elements such as lead, zinc, gold, silver, germanium, cadmium, arsenic, sulfur, thallium, fluorine, chlorine, iron, silicon, calcium, aluminum, and magnesium. According to the different physical and chemical properties of various elements and the content of valuable metals, a combined smelting process is determined. First, a side-blowing smelting furnace is used for high-temperature oxidation-reduction smelting. Lead, zinc, gold, silver, germanium, cadmium, and arsenic enter the intermediate product soot, impurity elements thallium, fluorine, and chlorine are separated into the flue gas, sulfur in the oxidized ore is sent into the medium-concentration flue gas sulfuric acid production system in the form of sulfur dioxide flue gas to produce concentrated sulfuric acid, and impurity iron, silicon, calcium, aluminum, and magnesium oxides are separated to form slag. Then, by applying the advantages of the lead-zinc combined smelting process, pyrometallurgy is used to smelt lead, gold, and silver to produce crude lead, and hydrometallurgy is used to produce zinc and cadmium germanium, ultimately achieving the purpose of comprehensively recovering valuable metals such as lead, zinc, gold, silver, germanium, and cadmium. The lower the lead-zinc grade in the oxidized ore and the higher the content of iron, silicon, calcium, aluminum, and magnesium elements, the more difficult it is to control the smelting process, the lower the metal recovery rate, the higher the energy consumption, and the higher the slag output.

[0031] The embodiment of the present application provides a method for comprehensively recovering low-grade lead-zinc oxidized ore resources, which has at least the following beneficial effects:

[0032] 1. In the present application, after the low-grade lead-zinc oxidized ore is proportioned with other materials in a specific ratio, all the materials are melted and initially reacted using a side-blowing smelting furnace, and the generated slag flows into the fuming furnace; in the fuming furnace, the metals in the slag are further reduced and volatilized, and finally high-purity metal products are obtained. The comprehensive recovery combined process of the entire side-blowing smelting furnace + fuming furnace combines the advantages of the wide raw material applicability of the side-blowing smelting furnace and the high metal recovery rate and large production capacity of the fuming furnace, improves the recovery rates of lead and zinc in the low-grade lead-zinc oxidized ore, and simultaneously co-treats silver, germanium, and cadmium, realizing the comprehensive recovery of low-grade lead-zinc oxidized ore resources;

[0033] 2. In the present application, sulfur in the oxidized ore is sent into the medium-concentration flue gas sulfuric acid production system in the form of sulfur dioxide flue gas through a side-blowing smelting furnace. Compared with the traditional process of low-concentration sulfur dioxide flue gas entering the tail gas desulfurization system, the tail gas treatment cost is lower, and it is more suitable for large-scale industrial production;

[0034] 3. In the present application, lead, zinc, silver, and germanium metals are recovered through the comprehensive recovery process of the side-blowing smelting furnace and the fuming furnace. Compared with the direct smelting process of the fuming furnace, the mineral treatment capacity is large, enabling the comprehensive recovery and utilization of valuable metals in low-grade lead-zinc oxidized ore through the comprehensive recovery process, and it is suitable for large-scale industrial production;

[0035] 4. In the present application, by controlling the ratio of the mixed ore raw materials, controlling the slag type, smelting temperature, and smelting cycle in the process, and regulating the key process control parameters in the entire lead-zinc smelting system, the recovery rate of lead in the low-grade lead-zinc oxidized ore is greater than 95%, and the recovery rate of zinc is greater than 93%. Compared with the traditional direct smelting process of low-grade oxidized ore using a fuming furnace, the recovery rates of lead and zinc are improved;

[0036] 5. This application directly sells lead ingots, zinc ingots and germanium concentrates, and uses the fuming furnace tailings as raw materials for the building materials and cement industry, generating zero hazardous waste and zero solid waste;

[0037] 6. This application is applicable to the smelting of low-grade lead-zinc oxide ores with a total lead-zinc grade greater than 10%. There is no longer a strict limit on whether the zinc content is greater than the lead content. In the traditional rotary kiln process, the total lead and zinc content of the raw materials must reach more than 48% and the zinc content is greater than the lead content. Compared with the two, the raw materials of this application have a wider applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the process of the present invention.

[0039] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] Test steps

[0042] S1, mixing low-grade lead-zinc oxide ore, hydrometallurgical zinc leaching residue, iron slag, lump coal, quartz sand and secondary zinc-containing materials in a mass ratio of 4:4:2:2:2:1 to obtain a mixed ore; the particle size of the low-grade lead-zinc oxide ore is ≤10mm; the sum of the lead and zinc grades in the low-grade lead-zinc oxide ore is greater than 10%, and the calcium grade is less than 35%; the secondary zinc-containing materials include any two or more of zinc-containing iron slag, zinc-containing sulfate slag and pyrometallurgical lead slag; the moisture content in the mixed ore is less than 18%;

[0043] S2, adding natural gas and oxygen-enriched air into the side-blown smelting furnace, feeding the mixed ore in S1 into the side-blown smelting furnace, and obtaining high-lead smoke and liquid zinc-containing slag after smelting;

[0044] S3, high pressure air and pulverized coal are introduced into the fuming furnace A, the temperature is controlled at 1150-1250°C, the liquid zinc-containing slag in S2 is sent to the fuming furnace A, and zinc oxide dust A is obtained after smelting;

[0045] S4. After proportioning the high-lead soot, lead slag, iron slag, and lead concentrate in S2 at a mass ratio of 1:1:1:2, feed them into a top-blown smelting furnace. Inject pulverized coal into the top-blown smelting furnace, control the temperature at 950 - 1050 °C. After smelting, molten lead-rich slag is obtained. Then, periodically transport the molten lead-rich slag to a side-blown reduction furnace. Inject oxygen-enriched air and natural gas into the side-blown reduction furnace, add lump coal, control the temperature at 1050 - 1200 °C, and obtain crude lead and reduction furnace slag through reduction smelting; after electrolytic smelting and die-casting of the crude lead, lead ingots and silver ingots are obtained;

[0046] S5. Periodically feed the reduction furnace slag in S4 into a fuming furnace B. Inject pulverized coal and high-pressure air into the fuming furnace B to obtain zinc oxide soot B;

[0047] S6. Feed the zinc oxide soot A and the zinc oxide soot B into a hydrometallurgical zinc smelting system to obtain germanium concentrate, zinc-containing filtrate, iron slag, and lead slag. The lead slag and iron slag are returned to S4 for proportioning. After purification and impurity removal of the zinc-containing filtrate, supernatant and germanium-containing filter residue are obtained; after burning the germanium-containing filter residue, germanium concentrate is obtained;

[0048] After purification, electrolytic melting, and casting of the supernatant, zinc ingots are obtained.

[0049] Based on the above description, an embodiment of a comprehensive recovery method for low-grade lead-zinc oxide ore resources of the present invention is proposed.

[0050] First Embodiment

[0051] In this embodiment, a feasibility test is conducted;

[0052] Test Steps

[0053] S1. Proportion the low-grade lead-zinc oxide ore, hydrometallurgical zinc leaching residue, iron slag, lump coal, quartz sand, and secondary zinc-containing materials at a mass ratio of 4:4:2:2:2:1 to obtain a mixed ore; for every 60 tons of the mixed ore, 16t of low-grade lead-zinc oxide ore, 16t of hydrometallurgical zinc leaching residue, 8t of iron slag, 8t of lump coal, 8t of quartz sand, and 4t of secondary zinc-containing materials need to be added; the particle size of the low-grade lead-zinc oxide ore ≤ 10mm; the sum of lead and zinc grades in the low-grade lead-zinc oxide ore is greater than 10%, and the calcium grade is less than 35%; the secondary zinc-containing materials include any two or more of zinc-containing iron slag, zinc-containing sulfuric acid slag, and lead smelting slag by fire; the moisture content in the mixed ore < 18%;

[0054] S2. Add the mixed ore into the side-blown smelting furnace in smelting at a constant speed of 27t / h. Add natural gas and oxygen-enriched air into the side-blown smelting furnace; control the process conditions for smelting low-grade lead-zinc oxide ore in the side-blown smelting furnace: the pressure of the natural gas input is 0.2 - 0.4MPa, and the flow rate is 1000 - 1400Nm 3 / h; the pressure of the oxygen-enriched air is 0.18 - 0.35MPa, and the flow rate is 9000 - 10000Nm 3 / h. The smelting temperature is 1150 - 1350 °C, and the concentration of oxygen-enriched air is 53%;

[0055] Feed the mixed ore in S1 into the side-blown smelting furnace. The smelting cycle is 3 hours per furnace. Let the molten slag produced by smelting flow through the slag launder to the fuming furnace A. The difference in the depth of the slag pool before and after slag discharging is > 0.6 m. The sulfur dioxide flue gas produced by the melting furnace smelting is cooled by the waste heat boiler and collected by the electrostatic precipitator, and then sent to sulfuric acid production from flue gas; After smelting, high-lead dust and liquid zinc-containing slag are obtained; The high-lead dust produced is sent to the lead pyrometallurgy batching.

[0056] S3, Inject 24000 m 3 / h of high-pressure air and 4.5 t / h of pulverized coal into the fuming furnace A. The differential pressure of the secondary air before and after receiving the molten slag from the side-blown smelting furnace is > 10 KPa. Control the reduction and volatilization temperature at 1150 - 1250 °C; The smelting cycle is 3 hours per furnace. Produce zinc oxide dust containing lead, zinc, silver and germanium and supply it to the hydrometallurgical zinc system. The tailing slag is quenched with water and transported out for use in the building materials and cement industries;

[0057] Send the liquid zinc-containing slag in S2 to the fuming furnace A. After smelting, zinc oxide dust A is obtained;

[0058] For the reduction smelting of the fuming furnace A, the composition requirements of the waste slag type are: iron content 22 - 28%, silicon dioxide content 20 - 24%, calcium oxide content 12 - 18%.

[0059] S4, After proportioning the high-lead dust in S2 with lead slag, iron slag and lead concentrate according to the mass ratio of 1:1:1:2, feed it into the top-blown smelting furnace. The smelting cycle is 3 hours per furnace. Inject pulverized coal into the top-blown smelting furnace and control the temperature at 950 - 1050 °C. After smelting, molten lead-rich slag is obtained. Then, periodically transport the molten lead-rich slag to the side-blown reduction furnace. Inject oxygen-enriched air and natural gas into the side-blown reduction furnace, add lump coal, and control the temperature at 1050 - 1200 °C. After reduction smelting, crude lead and reduction furnace slag are obtained; After electrolytic smelting and die-casting of the crude lead, lead ingots and silver ingots are obtained;

[0060] S5, Periodically send the reduction furnace slag in S4 to the fuming furnace B. Inject pulverized coal and high-pressure air into the fuming furnace B to obtain zinc oxide dust B;

[0061] S6, Send the zinc oxide dust A and the zinc oxide dust B into the hydrometallurgical zinc system to obtain germanium concentrate, zinc-containing filtrate, iron slag and lead slag. The lead slag and iron slag are returned to S4 for batching. After the zinc-containing filtrate is purified to remove impurities, supernatant and germanium-containing filter residue are obtained; The germanium-containing filter residue is roasted to obtain germanium concentrate;

[0062] The supernatant is purified, electrolytically melted and cast to obtain zinc ingots.

[0063] The material composition is as follows:

[0064] Table 1 Main Chemical Compositions of Leaching Residue in Hydrometallurgical Zinc Smelting (Dry Basis, %)

[0065] Element Zn Pb Fe Cu S As Sb Cd w％ 12.20 6.70 23.23 0.09 9.31 0.31 0.010 1.37 Element <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> Ag* Ge* F Cl w％ 3.20 4.16 0.92 0.9 106 190 0.050 0.050

[0066] The units of Ge* and Ag* are g / t

[0067] Table 2 Main Chemical Compositions of Low-Grade Lead-Zinc Oxide Ore (Dry Basis, %)

[0068] Element Zn Pb Fe Cu S As Sb Cd w％ 16.42 5.57 11.60 0.01 5.25 0.16 0.010 0.031 Element <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> Ag* Ge* F Cl w％ 4.80 15.82 6.11 5.63 44 53 0.080 0.020

[0069] The units of Ge* and Ag* are g / t

[0070] The hydrometallurgical zinc smelting of zinc oxide fume dust is as described in the process.

[0071] The First Comparative Example

[0072] Compared with Example 1, when treating the same batch of low-grade lead-zinc oxide ore and leaching residue in hydrometallurgical zinc smelting with other processes, the test results are as follows:

[0073] Table 3 Energy Consumption Indexes of Common Processes for Treating Low-Grade Lead-Zinc Oxide Ore

[0074]

[0075]

[0076] In summary, as can be seen from Table 3, compared with several other smelting processes, the side-blown smelting furnace combined with the fuming furnace process of the present invention has a wide raw material applicability, a large mineral treatment capacity, a lead recovery rate greater than or equal to 98%, a zinc recovery rate of 88% - 94.5%, a silver recovery rate of 95% - 98%, a germanium recovery rate of 83%, and cadmium is recovered as sponge cadmium for productization.

[0077] The Second Comparative Example

[0078] Compared with Example 1, with all other conditions remaining completely unchanged, only another batch of low-grade lead-zinc oxide ore and leaching residue in hydrometallurgical zinc smelting are treated, and their main chemical compositions are as shown in the following table;

[0079] The side-blown smelting furnace + fuming furnace process in this application is compared separately with the direct smelting process of the fuming furnace (treating the same batch of low-grade lead-zinc oxide ore and leaching residue in hydrometallurgical zinc smelting), and the test results are as follows:

[0080] Table 4 Main Chemical Compositions of Leaching Residue (Dry Basis, %)

[0081] Element Zn Pb Fe Cu S As Sb Cd w％ 9.40 6.70 26.23 0.09 10.51 0.31 0.040 1.57 Element <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> Ag* Ge* F Cl w％ 4.20 4.16 0.97 0.92 113 195 0.060 0.050

[0082] The units of Ge* and Ag* are g / t

[0083] Table 5 Main Chemical Compositions of Oxide Ores (Dry Basis, %)

[0084] Element Zn Pb Fe Cu S As Sb Cd w％ 23.54 5.87 13.60 0.01 6.45 0.16 0.010 0.041 Element <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> Ag* Ge* F Cl w％ 4.90 17.83 6.21 5.41 47 39 0.070 0.030

[0085] The units of Ge* and Ag* are g / t

[0086] During the smelting process, comprehensive regulation is carried out according to the actual conditions such as the operating conditions of the whole-process equipment, negative pressure, slag bath depth, slag type, flue gas volume, temperature, SO2 concentration of sulfuric acid flue gas, and boiler evaporation capacity, as well as the cycle matching of the side-blown smelting furnace with upstream and downstream metallurgical furnaces. The addition amount of lump coal and the feeding rate of materials are adjusted in real time. Natural gas flow > 1200 Nm 3 / h; oxygen-enriched air concentration > 45%, oxygen-enriched air flow > 8000 Nm 3 / h.

[0087] Table 6 Energy Consumption Indexes of Common Processes for Treating Low-Grade Lead-Zinc Oxide Ores

[0088]

[0089] In summary, compared with the direct smelting process of the fuming furnace, the side-blown smelting furnace + fuming furnace process has a large mineral treatment capacity and a strong adaptability to the main metal grades of lead-zinc oxide ores; the lead-zinc metal recovery rate is higher, the recovery rate of lead is greater than or equal to 98%, the recovery rate of zinc is 88% - 94.5%, the recovery rate of silver reaches 95 - 98%, and the recovery rate of germanium reaches 83%.

[0090] It should be noted that although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A comprehensive recovery method for low-grade lead-zinc oxide ore resources, characterized in that, The method includes the following steps: S1, proportion low-grade lead-zinc oxide ore, zinc hydrometallurgy leaching residue, iron slag, lump coal, quartz sand and secondary zinc-containing materials according to a mass ratio of 4:4:2:2:2:1 to obtain a mixed ore; The sum of the lead and zinc grades in the low-grade lead-zinc oxide ore is greater than 10%, and the calcium grade is less than 35%; The secondary zinc-containing materials include any two or more of zinc-containing iron slag, zinc-containing sulfuric acid slag and lead smelting slag by pyrometallurgy; S2, feed the mixed ore in S1 into a side-blowing smelting furnace to obtain high-lead dust and liquid zinc-containing slag; S3, send the liquid zinc-containing slag in S2 to fuming furnace A, and obtain zinc oxide dust A after smelting; S4, after proportioning the high-lead dust in S2 with lead slag, iron slag and lead concentrate according to a mass ratio of 1:1:1:2, feed it into a top-blowing smelting furnace to obtain molten lead-rich slag, and then periodically transport the molten lead-rich slag to a side-blowing reduction furnace to obtain crude lead and reduction furnace slag; After electrolytic smelting and die-casting of the crude lead, lead ingots and silver ingots are obtained; S5, periodically feed the reduction furnace slag in S4 into fuming furnace B to obtain zinc oxide dust B; S6, feed the zinc oxide dust A and zinc oxide dust B into a zinc hydrometallurgy system to obtain germanium concentrate, zinc-containing filtrate, iron slag and lead slag. The lead slag and iron slag are returned to S4 for proportioning. After the zinc-containing filtrate is purified and the impurities are removed, supernatant and germanium-containing filter residue are obtained; The germanium-containing filter residue is calcined to obtain germanium concentrate; The supernatant is purified, electrolytically melted and cast to obtain zinc ingots.

2. The method according to claim 1, characterized in that, The mass ratio of FeO to SiO2 in the mixed ore is (1.3 - 1.5):1, and the mass ratio of CaO to SiO2 is (0.5 - 0.8):

1.

3. The method according to claim 1, wherein In the fuming furnace A described in S3, high-pressure air of 24,000 m 3 / h and pulverized coal of 4.5 t / h are input. The temperature inside the furnace is 1,150 - 1,250 °C, and the smelting cycle is 3 hours per furnace.

4. The method according to claim 1, characterized in that Pulverized coal is sprayed into the top-blowing smelting furnace in S4, and the temperature is controlled at 950 - 1050 °C. The conveying period of the molten lead-rich slag is 2.5 - 3.5 hours, and the temperature in the side-blowing reduction furnace is 1050 - 1200 °C.

5. The method according to claim 1, wherein Pulverized coal and high-pressure air are injected into fuming furnace B in S5, the smelting temperature is 1100 - 1250 °C, and the smelting period is 1.5 - 3 h / furnace.

6. The method according to any one of claims 3-5, characterized in that, The calorific value of the pulverized coal is 4000 - 6500 kcal·kg -1 ; the fixed carbon content of the pulverized coal is ≥50%, the sulfur content is ≤2.5%, the proportion of volatile matter is 10% - 25%, the proportion of moisture is ≤2%, the proportion of ash is ≤30%, and the particle size ≤200 mesh accounts for more than 70% of the total volume of the pulverized coal.

7. The method according to any one of claims 3-5, characterized in that The supply system of the pulverized coal is a Redek powder coal injection system, and the given amount of pulverized coal is 2 - 5.5 t / h.

8. The method according to claim 1, wherein The particle size of the low-grade lead-zinc oxide ore in S1 is ≤10 mm; the moisture content of the secondary zinc-containing materials is 10% - 18%; the moisture content in the mixed ore is <18%.

9. The method according to claim 1, wherein The smelting temperature of the side-blowing smelting furnace in S2 is 1150 - 1350 °C, and the smelting period is 2 - 4 h / furnace.

10. The method according to claim 1, wherein Smelting waste slag is generated in fuming furnace A and fuming furnace B. After the smelting waste slag is water-quenched, water-quenched slag is obtained, and the water-quenched slag is recycled as a raw material for cement building materials.

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